Search

This paper is devoted to the study of curvature properties of Hayward black hole (briefly, HBH) spacetime, which is a solution of Einstein field equations (briefly, EFE) having non-vanishing cosmological constant. We have proved that the HBH spacetime is an Einstein manifold of level 2, 2-quasi Einstein, generalized quasi-Einstein and Roter type manifold. Also, it is shown that the nature of the HBH spacetime is pseudosymmetric and it obeys several types of pseudosymmetries, such as, pseudosymmetry due to concircular, conformal and conharmonic curvature (i.e., F ⋅ F = L Q (g , F) for F = W , C , K with a smooth scalar function L), and it also possesses the relation R ⋅ R − L Q (g , C) = Q (S , R). It is engrossing to mention that the nature of energy momentum tensor of the HBH spacetime is pseudosymmetric. On the basis of curvature related properties, we have made a comparison among Reissner–Nordström spacetime, interior black hole spacetime and HBH spacetime. It is noteworthy to mention that the gravitational force of the point-like global monopole spacetime is much stronger than that of HBH spacetime. Also, it is shown that the HBH spacetime admits an almost η -Ricci soliton as well as an almost η -Ricci-Yamabe soliton. Finally, an elegant comparative study is delineated between the HBH spacetime and the point-like global monopole spacetime with respect to different kinds of symmetry, such as, motion, curvature collineation, curvature inheritance etc. • This paper aims to the study of curvature properties of Hayward black hole spacetime. • We have proved that the spacetime is an Ein(2), 2-quasi Einstein and Roter type. • Also shown that the nature of the spacetime obeys several types of pseudosymmetries. • We have compared Reissner–Nordström, interior black hole and HBH spacetime. • Also, the HBH spacetime admits an almost η -Ricci and almost η -Ricci-Yamabe solitons. [ABSTRACT FROM AUTHOR]

Gravitational weak lensing around a hairy black hole has been deeply studied in the presence of a plasma medium. The obtained results have shown that the effect of parameters a and l 0 on the deflection angle of light rays around the black hole in hairy spacetime is perceptible. With an increase of parameter a the deflection angle of photon orbits decreases, and the effect of plasma on the deflection angle is the opposite. Here, we discussed different types of plasma distributions: uniform ω e = c o n s t , Singular Isothermal Sphere medium, 1 / r and Non-Singular Isothermal gas sphere plasma. Additionally, The total magnification of the image source due to gravitational lensing has been also studied taking into account the effect of deviation parameter a and parameter l 0 related to hairy spacetime in the presence of plasma around the black hole. • Gravitational weak lensing around a hairy black hole has been deeply studied in the presence of a plasma medium. • The obtained results have shown that the effect of parameters a and I 0 on the deflection angle of light rays around the black hole in hairy spacetime is perceptible. • Here, we discussed different types of plasma distributions: uniform ω e = const , Singular Isothermal Sphere medium, 1 /r, and Non-Singular Isothermal gas sphere plasma. • The total magnification of the image source due to gravitational lensing has been also studied. [ABSTRACT FROM AUTHOR]

• Dynamical equations of thin-shell wormholes constructed from two identical copies of the Hayward-de Sitter regular black hole through cut and paste techniques are studied. • The stability of the Hayward-de Sitter wormhole is analyzed about the static solution of linear perturbation at the wormhole throat. • The variable modified generalized Chaplygin gas equation of state is considered. • The existence of Bardeen-de Sitter parameters and the equation of state parameters seems to • enlarge the stability regions. A dynamical equation of thin shell wormholes constructed by grafting together two identical copies of the Hayward-de Sitter regular black hole through cut and paste techniques are studied. The stability analysis under the linear perturbation around the static solution at the wormhole throat with two different equations of state, such as a variable modified generalized Chaplygin gas and a polytropic gas are discussed. It is observed that the stability configuration is possible for a suitable choice of the parameters involved in both equations of state as well as the metric spacetime. [ABSTRACT FROM AUTHOR]

• Dynamical equation of thin-shell wormhole joining two identical copies of non-singular Bardeen-de Sitter spacetime is constructed. • The stability of the Bardeen-de Sitter wormhole is analyzed about the static solution of linear perturbation at the wormhole throat. • The variable modified generalized Chaplygin gas equation of state is considered. • The existence of Bardeen-de Sitter parameters and the equation of state parameters seems to enlarge the stability regions. A dynamical equation of thin-shell wormhole joining two identical copies of non-singular Bardeen-de Sitter black hole spacetime through the cut and paste techniques is constructed. The stability of the Bardeen-de Sitter wormhole, as the static solution of linear perturbation at the wormhole throat and a variable modified generalized Chaplygin gas equation of state, is analyzed. The existence of stability configurations depends on the particular values of different parameters involved in the equation of state as well as the space-time metric performed. The existence of Bardeen-de Sitter parameters and the equation of state parameters to enlarge the stability regions may be obtained. [ABSTRACT FROM AUTHOR]

• Two new exact and analytic solutions of the Einstein–Maxwell field equations describing compact anisotropic charged stars satisfying the Karmarkar condition in the background of Bardeen black hole geometry are studied. • The validity of the solutions is verified by performing several physical tests. • The solutions satisfy all the physical requirements necessary for well-behaved models. • The models represent neutron star in Vela X-1. In this paper, we present two new exact and analytic solutions of the Einstein–Maxwell field equations describing compact anisotropic charged stars satisfying the Karmarkar condition in the background of Bardeen black hole geometry. The solutions are composed of two parts: The inner region of the star is described by class I Karmarkar space-time, while exterior of the star is characterized by both the Bardeen and the Reissner–Nordstrom space-times. Physical analysis of the matter and thermodynamical variables show that the models are well-behaved. For our parametric set of values, we conclude that the Bardeen black hole metric can be used as an alternate to the exterior Reissner–Nordstrom metric. [ABSTRACT FROM AUTHOR]